3.1 Introduction of ASP
Active Server Pages is the abbreviation of ASP. It is a Microsoft technology that enables the development of dynamic web pages. ASP files contain HTML, text, XML and scripts used for developing web pages. These tags provide dynamic content for web development. An ASP file has .asp file extension. ASP programs runs inside Internet Information Services (IIS).
Active Server Pages enables server side scripting for IIS. It provides native support for both VBScript and Jscript. Server executes the scripts present in the ASP files.
Advantages of using ASP
- User can dynamically edit, change, or update the content of a web page
- No client side constraints are necessary for developing the ASP application
- It helps user access any database and send the results to the web browser
- It provides security as the ASP code cannot be viewed from the web browser
- ASP programming minimizes the network traffic
- It responds the user queries, data submitted from the HTML forms
- Web pages can be customized for better individual use
- ASP is simple to use and the development time is saved.
3.2 Working of ASP
The web architecture of ASP is represented. The client/user send the HTTP request to the IIS for processing the ASP page. IIS identifies the scripting language used for developing the ASP page. Depending on the scripting language, the file is sent to the ActiveX scripting engine. The engine performs the operations and the result is sent back to the IIS. The interchange server checks for the data objects present in the page.
The objects are transferred to the ActiveX Data objects. Active objects are sent to the database for performing the database operations. The database sends the result to the data objects. IIS receives the expected result through database. IIS send the result back to the client/user through the HTTP response object. Thus, this is the execution cycle of the ASP
3.3 ASP Objects
There are several ASP objects used for writing ASP code. Each object has its unique functionality. The list of ASP objects is mentioned below:
- ASP Response object
- ASP Request object
- ASP application object
- ASP session object
- ASP error object
- ASP FileSystem object
- ASP TextStream object
- ASP Drive object
- ASP File object
- ASP Folder object
- ASP Dictionary
1) ASP Response object:
The ASP Response object is used to send the server output to the user. The properties and methods of the ASP Response object with their syntax are mentioned below:
Properties of ASP Response object
Property | Description | Syntax |
Buffer | It is used to specify that the page can be buffered | response.Buffer[=flag], where flag is Boolean value. |
CacheControl | It is used to cache the output generated by ASP page through proxy server | response.CacheControl[=control_header], where control header value can be private or public |
Charset | It appends the name of character set to the content header in Response object | response.Charset(charsetname), where charset is string that specifies a character set on the page |
ContentType | It sets the HTTP content type for the Response object | response.ContentType[=contenttype], where contentype is string variable |
Expires | It defines the duration of page caching before the browser expires | response.Expires[=number], where number is minutes before the page expires |
ExpiresAbsolute | It sets the date and time for a cached page to expire on the browser | response.ExpiresAbsolute[=[date][time]], where date and time are values when the page will expire |
IsClientConnected | It indicates whether the client is disconnected from the browser | response.IsClientConnected |
Status | It specifies the value of the status line returned by server | response.Status=statusdescription, where status description is a three digit code |
Property of ASP Request object
Property | Description | Syntax |
TotalBytes | It returns the total number of bytes the client sent in the request body | varbytes=Request.TotalBytes |
Method of ASP Request object
Method | Description | Syntax |
BinaryRead | It is used to retrieve the data sent to the server | Request.BinaryRead(count), where count is the number of bytes to be read from client |
Collections of ASP Request object
Collection | Description | Syntax |
ClientCertificate | It contains the field values stored in the client certificate |
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Cookies | It is used to get or set cookie values | Response.Cookies(name)[(key)|.attribute] =value |
Form | It is used to retrieve the values of form elements | Request.Form(element)[(index)|.Count] |
QueryString | It contains all the variable in HTTP query string | Request.QueryString(variable)[(index)| .Count] |
ServerVariables | It contains all the server variables | Request.ServerVariables(server_variable) |
3) ASP Application object:
The application consists of many ASP files. The purpose of the Application object is to combine these files together. The Application object stores variables from the ASP pages. Only one application object is used among all the users. The information stored in the Application object can be accesses from any page. The Application objects collections, events and methods are mentioned below:
Collections of ASP Application object:
Collection | Description | Syntax |
Contents | It contains all the items appended to the application through script command | Application.Contents(Key), where key is the name of the item to retrieve |
StaticObjects | It contains all the objects appended to the application with HTML <object> tag | Application.StaticObjects(Key), where key is the name of the item to retrieve |
Methods of ASP Application object
Method | Description | Syntax |
Contents.Remove | It deletes an item from the Content collection | Application.Contents.Remove (name|index), conatins the value to retrieved |
Contents.RemoveAll() | It removes all items from the Content collection | Appliations.Content.RemoveAll() |
Lock | It prevents the user from modifying the variable | Application.Lock |
Unlock | It helps user to modify the variable | Application.Unlock |
Events of ASP Application object:-
Event | Description | Syntax |
Application_OnStart | It occurs before the first session is created | Application_OnStart |
Application_OnEnd | It occurs when the application ends | Application_OnEnd |
4) ASP Session object:
The session object is used to store information about the user session. A cookie is created for every user. The cookie contains all the information required for user identification. The interface providing this feature is session object.
The collections, properties, methods and events of the ASP Session object are mentioned below:
Collections of ASP Session object
Collection | Description | Syntax |
Contents | It contains items appended to the session through command object | Session.Contents(Key), Where Key is the name of the item to be retrieved |
StaticObjects | It contains all the objects appended to the session through HTML <object> tag | Application.StaticObjects(Key), Where Key is the name of the item to be retrieved |
Properties of ASP Session object
Property | Description | Syntax |
CodePage | It specifies the character set used to display dynamic content | Session.CodePage(=CodePage), Where CodePage is for the system running the script |
LCID | It sets or returns an integer specifying location or region | Session.LCID(=LCID), where LCID is a locale identifier |
SessionID | It returns a unique id for each user | Session.SessionID |
Timeout | It sets or returns the timeout period for the session object | Session.Timeout[=nMinutes] |
Methods of ASP Session object
Method | Description | Syntax |
Abandon | It destroys the user session | Session.Abandon |
Contents.Remove | It deleted the item from the Contents collection | Session.Contents.Remove (name|index) |
Contents.RemoveAll() | It deleted all the items from the Contents collection | Session.Contents.RemoveAll() |
Events of ASP Session object
Event | Description | Syntax |
Session_OnStart | It occurs when the server creates a session | Session_OnStart |
Session_OnEnd | It occurs when the session ends | Session_OnEnd |
5) ASP Server object
The ASP Server object is used to access the properties and methods on the server. The properties and methods of the ASP Server object are mentioned below
Property of ASP Server object
Property | Description | Syntax |
ScriptTimeout | It sets or returns the maximum number of seconds a script can execute | Server.ScriptTimeout [=NumSeconds] |
Methods of ASP Server object
Method | Description | Syntax |
CreateObject | It creates an instance of an object | Server.CreateObject(progID), where progID is the object type to be created |
Execute | It executes the ASP file from another ASP file | Server.Execute(path), where path is the location of the ASP file |
GetLastError() | It returns an ASPError object for the error condition | Server.GetLastError() |
HTMLEncode | It applies HTML encoding to a string | Server.HTMLEncode(string), where string is to be encoded |
MapPath | It maps a specified path to the physical path | Server.MapPath(path), where path is relative or virtual |
Transfer | It sends information from ASP file to another file | Server.Transfer(path), where path is the location of the ASP file |
URLEncode | It applies the URL encoding rules to the specified string | Server.URLEncode(string), Where the string is to encoded |
6) ASP Error object
The ASP Error object is used to display detail information of error occurring in the ASP page. The properties of the ASP Error object is mentioned below
Properties of ASP Error object
Property | Description | Syntax |
ASPCode | It returns an error code generated by IIS | ASPError.ASPCode() |
ASPDescription | It returns a detail description of the error | ASPError.ASPDescription() |
Category | It returns the source of the error | ASPError.Category() |
Column | It returns the column position within the ASP file | ASPError.Column() |
Description | It returns a short description of the error | ASPError.Description() |
File | It returns the name of the ASP file generating the error | ASPError.File() |
Line | It returns the number of lines that generated the error | ASPError.Line() |
Number | It returns the standard COM error code for the error | ASPError.Number() |
Source | It returns the actual source code of the line | ASPError.Source() |
7) ASP FileSystem object
The ASP FileSystem object is used to access the file system on a server. These objects can manipulate files, folders, and directory paths. File system information can be retrieved using the FileSystem object. The properties and methods of the FileSystem object are mentioned below
Property of ASP FileSystem object
Property | Description | Syntax |
Drives | It returns a collection of drive objects on the system | [drivecol1=]FileSystemObject.Drives |
Methods of ASP FileSystem object
Method | Description | Syntax |
BuildPath | It appends a name to an existing path | [newpath=]FileSystemObject. BuildPath(path,name) |
CopyFile | It copies one or more files from one location to another | FileSystemObject.CopyFile source, destination[,overwrite] |
CopyFolder | It copies one or more folder in the system | FileSystemObject.CopyFolder Source, destination[,overwrite] |
CreateFolder | It creates a new folder | FileSystemObject.CreateFolder (name) |
CreateTextFile | It creates a new text file in the current folder | FileSystemObject.CreateTextFile (filename[,overwrite[,Unicode]]) |
DeleteFile | It deleted the file specified in the parameters list | FileSystemObject.DeleteFile( Filename[, force]) |
DeleteFolder | It deleted the folders specified in the parameter list | FileSystemObject.DeleteFolder( Foldername[, force]) |
DriveExists | It checks for the existence of the specific drive | FileSystemObject.DriveExists( drive) |
FileExists | It checks for the existence of the specific file | FileSystemObject.FileExists( filename) |
FolderExists | It checks for the existence of the specific folder | FileSystemObject.FolderExists( foldername) |
GetAbsolutePathName | It returns the complete path from to root to the destination | FileSystemObject.GetAbsolutPath Name(path) |
GetBaseName | It returns the base name of the file or folder | FileSystemObject.GetBaseName (path) |
GetDrive | It returns the drive object for the specific parameter | FileSystemObject.GetDrive (drivespec) |
GetDriveName | It returns the drive name of the specific path | FileSystemObject.GetDriveName (path) |
GetExtensionName | It returns the file extension name for the component | FileSystemObject.GetExtension Name(path) |
GetFile | It returns the file object for the specified path | FileSystemObject.GetFile(path) |
GetFileName | It returns the file or folder for the last component in the specified path | FileSystemObject.GetFileName (path) |
GetFolder | It returns the folder object for the specific path | FileSystemObject.GetFolder (path) |
GetParentFolder | It returns the name of the parent folder in the specific path | FileSystemObject.GetParent FolderName(path) |
GetSpecialFolder | It returns the path of Windows special folders | FileSystemObject.GetSpecial Folder(foldername) |
GetTempName | It returns a randomly generated temporary file | FileSystemObject.GetTemp Name |
MoveFile | It moves files to different location | FileSsyetnObject.MoveFile Source, destination |
MoveFolder | It moves folders to different location | FileSystenObject.MoveFolder Source, destination |
OpenTextFile | It opens the specific file and returns the TextStream object | FileSystemObject.OpenTextFile (fname, mode, create, format) |
8) ASP TextStream object
The ASP TextStream object is used for accessing the contents of the text file. The CreateTextFile or OpenTextFile methods are used to create the instance of the TextStream object. The properties and methods of the ASP TextSteam object are as mentioned below
Properties of ASP TextStream object
Property | Description | Syntax |
AtEndOfLine | It returns Boolean value depending on the file pointer position | TextStreamObject. AtEndOfLine |
AtEndOfStream | It returns true if the file pointer is at the end of the file | TextStreamObject. AtEndOfStream |
Column | It returns the column number of the current character position | TextStreamObject. Column |
Line | It returns the current line number in the file | TextStreamObject.Line |
Methods of ASP TextStream object
Method | Description | Syntax |
Close | It closes the TextStream file | TextStreamObject.Close |
Read | It reads the specific number of characters from the file | TextStreamObject.Read (numchar) |
ReadAll | It reads the complete TextStream file | TextStreamObject.ReadAll |
ReadLine | It reads one line from the TextStream file | TextStreamObject.ReadLine |
Skip | It skips the number of characters specified while reading the file | TextStreamObject.Skip (numchar) |
SkipLine | It skips a line while reading a TextStream file | TextStreamFile.SkipLine |
Write | It writes the specific text to the TextStream file | TextStreamObject.Write (text) |
WriteLine | It writes the specific text and an new line character | TextStreamObject.WriteLine (text) |
WriteBlankLines | It writes the specific number of new line character to the file | TextStreamObject.Write BlankLines(numlines) |
9) ASP Drive object
The ASP Drive object is used to return information about network share or local drive. The information regarding driver type, free space, serial number, volume name is specified in the Drive object.
Properties of ASP Drive object
Property | Description | Syntax |
AvailableSpace | It returns the space available for the user | DriveObject.AvailableSpace |
DriveLetter | It returns the letter indicating the local drive | DriveObject.DriveLetter |
DriveType | It returns the value indicating the drive type | DriveObject.DriveType |
FileSystem | It returns the file system in use for the specific drive | DriveObject.FileSystem |
FreeSpace | It returns the amount of free space for the user | DriveObject.FreeSpace |
IsReady | It returns true if the specified drive is ready | DriveObject.IsReady |
Path | It returns the path for a specific drive, file or folder | DriveObject.Path, FolderObject.Path FileObject.Path |
RootFolder | It returns the root folder of the specific drive | DriveObject.RootFolder |
SerialNumber | It returns the serial number of the specific drive | DriveObject.SerialNumber |
ShareName | It returns the network share name for the specific drive | DriveObject.ShareName |
TotalSize | It returns the total size, in bytes for specific drive | DriveObject.TotalSize |
VolumeName | It returns the volume name of the specific drive | DriverObject.VolumeName [=newname] |
10) ASP File object
The ASP File object is used to return information for the specified file. User must create an instance of the File object through FileSystemObject. Next, instantiate the File object through the GetFile method. The properties and methods of the ASP File object are mentioned below
Properties of ASP File object
Property | Description | Syntax |
Attributes | It sets or returns the attributes of a specific file | FileObject.Attributes [=newattributes] |
DateCreated | It returns the date and time of the file creation | FileObject.DateCreated |
DateLastAccessed | It returns the date and time when the file was last accessed | FileObject.DateLastAccessed |
DateLastModified | It returns the date and time when the file was last modified | FileObject.DateLastModified |
Drive | It returns the drive letter of the drive where the file is located | FileObject.Drive |
Name | It is used to set or return the name of the specific file | FileObject.Name [=newname] |
ParentFolder | It is used to return the folder object for the parent of the file | FileObject.ParentFolder |
Path | It returns the path for the specified file | FileObject.Path |
ShortName | It is used for returning short name of the specific file | FileObject.ShortName |
ShortPath | It is used for returning short path of the specific file | FileObject.ShortPath |
Size | It returns the size of the file in bytes | FileObject.Size |
Type | It returns the type of the specific file | FileObject.Type |
Methods of ASP File object
Method | Description | Syntax |
Copy | It copies the file from the defined location | FileObject.Copy (destination[, overwrite]) |
Delete | It deleted the specified file | FileObject.Delete[(force)] |
Move | Moves the specified file in the system | FileObject.Move (destination) |
OpenAsTextStream | It opens a specific file and returns the TextStream object | FileObject.OpenAsText Steam(mode, format) |
11) ASP Folder object
The ASP Folder object is used to return information about the folder specified by the user. User must create an instance of the Folder object through FileSystemObject. Next, instantiate the Folder object through the GetFolder method. The collections, properties and methods of the ASP Folder object are mentioned below
Collections of ASP Folder object
Collection | Description | Syntax |
Files | It returns the collection of all files in the specific folder | FolderObject.Files |
SubFolders | It returns the collection of all subfolders in the specific folder | FolderObject.SubFolders |
Properties of ASP Folder object
Property | Description | Syntax |
Attributes | It sets or returns the value for a specific folder | FolderObject.Attributes [=newattributes] |
DateCreated | It returns the date and time of the folder creation | FolderObject.DateCreated |
DateLastAccessed | It returns the date and time when the folder was last accessed | FolderObject.DateLastAccessed |
DateLastModified | It returns the date and time when the folder was last modified | FolderObject.DateLastModified |
Drive | It returns the drive letter of the drive where the folder is located | FolderObject.Drive |
IsRootFolder | It returns true if the specified folder is root | FolderObject.IsRootFolder |
Name | It is used to set or return the name of the specific folder | FolderObject.Name [=newname] |
ParentFolder | It is used to return the folder object for the parent of the folder | FolderObject.ParentFolder |
Path | It returns the path for the specified folder | FolderObject.Path |
ShortName | It is used for returning short name of the specific folder | FolderObject.ShortName |
Size | It returns the size of the folder in bytes | FolderObject.Size |
Type | It returns the type of the specific folder | FolderObject.Type |
ShortPath | It is used for returning short path of the specific folder | FolderObject.ShortPath |
Methods of ASP Folder object
Method | Description | Syntax |
Copy | It copies the folder from the defined location | FolderObject.Copy (destination[, overwrite]) |
Delete | It deleted the specified folder | FolderObject.Delete[(force)] |
Move | Moves the specified folder in the system | FolderObject.Move (destination) |
CreateTextFile | It creates a new text file in the current folder and returns a TextStream object | FolderObject.CreateTextFile (filename[,overwrite[, Unicode]]) |
12) ASP Dictionary object
The Dictionary object is used for storing information in name/value pair. The items in the Dictionary objects are identified through keys. Items automatically shift up when the item is deleted from the Dictionary. Dictionary has built in functions that provide easy processing. The properties and methods of the ASP Dictionary object are as mentioned below:
Properties of ASP Dictionary object
Property | Description | Syntax |
CompareMode | It sets or returns the comparison mode for comparing keys in Dictionary | DictionaryObject.Compare Mode[=compare] |
Count | It returns the number of key/item pair in the object | DictionaryObject.Count |
Item | It sets or returns the value of an item | DictionaryObject.Item (Key)[=newitem] |
Key | Used to set the new value for an existing key value | DictionaryObject.Key(key) =newkey |
Methods of ASP Dictionary object
Method | Description | Syntax |
Add | It adds a new key/item pair to a Dictionary object | DictionaryObject.Add (key, item) |
Exists | It returns a Boolean value if the key exists | DictionaryObject.Exists (key) |
Items | It returns an array of all items in the Dictionary object | DictionaryObject.Items |
Keys | It returns an array of all keys in the Dictionary object | DictionaryObject.Keys |
Remove | It removes one specific item from the key/item pair | DictionaryObject.Remove (key) |
RemoveAll | It removes all key/item pairs in the Dictionary object | DictionaryObject.RemoveAll |
3.4 Sample Program of ASP
3.4.1 Basic syntax of ASP
The ASP code is written by using HTML tags. It contains server scripts inside delimiters. The delimiters are denoted as <% and %>. The scripts are executed on the server and contains expressions, statements, procedures, and operators for the respective scripting language.
The response.write command is used to write output to the browser. The example of the response.write command is mentioned below:
<html> <body> <% response.write(“Welcome to ASP”) %> </body> </html>
3.4.2 ASP Procedures
The ASP Procedures are created using the sub keyword. The end of the procedure is defined by end sub keyword. The example of ASP Procedure is mentioned below:
<html> <head> <% sub adproc ( a,b ) response.write(a+b) end sub %> </head> <body> <p>Output : <%call adproc ( 2,3 ) %></p> </body> </html>
3.4.3 ASP Functions
User should insert <%@language=”javascript”%> line before the <html> tag. The function keyword is used for creating ASP functions. The example of ASP function is mentioned below:
<%@language =”javascript %> <html> <head> <% function divno(no1, no2) { Response.Write(no1/no2) } %> </head> <body> <p>Output : <%divno(4,6)%></p> </body> </html>
3.4.4 ASP Forms and User Input
Information from the ASP forms can be retrieved using Request objects. The Request.QueryString and Request.Form commands are used to retrieve the form values.
Request.QueryString: The command is used to collect values in a form with the ‘get’ method. Information sent from a form through the get method is visible to all the users. The example of HTML form is shown below:
<form method=”get” action=”Academic.asp”> Course:<input type=”text” name=”MCA”><br> Grade: <input type=”text” name=”A” ><br><br? <input type=”submit” value=”Submit”> </form>
The script in the Academic.asp is mentioned below:
<body> Report Page <% response.write(request.querystring(“MCA”)) response.write( “ “ & request,querystring(“A”)) %> </body>
The output will be displayed as :
Report Page MCA A
Request.Form: The command is used to collect values using post method from a form. Information sent through the post method is invisible to other users. Unlimited data can be sent through the method. The script in the Academic script is mentioned below
<body> Report Page <% response.write(request.form(“course”)) response.write(“ “ & request.form(“A”) ) %> </body>
3.3.5 ASP Cookies
A cookie is a file embedded by the server on the users system. It is used to identify the user. For every web page request, a cookie is sent to the server. Using ASP, user can create and retrieve cookie values.
The Response.Cookies command is used to create cookies. The example of cookie creation is mentioned below:
<% Response.Cookies(“City”) = “London” %>
To retrieve the cookie values use the Request.Cookies command. The example to retrieve cookie values is shown below:
<% cname = Request.Cookies(“Country”) response.write(“Countryname=” & cname) %>
When the cookie has multiple values , the cookie has Keys. The example of cookie collection as data is mentioned below:
<% Response.Cookies(“data”)(“Course”)=”MBA” Response.Cookies(“data”)(“Grade”)=”A” Response.Cookies(“data”)(“city”)=”London” Response.Cookies(“data”)(“country”)=”UK” %>